title: Retrograde autologous priming for cardiopulmonary bypass: a safe and effective means of decreasing hemodilution and transfusion requirements.
abstract: OBJECTIVE
  The obligatory hemodilution resulting from crystalloid priming of the cardiopulmonary bypass circuit represents a major risk factor for blood transfusion in cardiac operations. We therefore examined whether retrograde autologous priming of the bypass circuit would result in decreased hemodilution and red cell transfusion.
  
  
  METHODS
  Sixty patients having first-time coronary bypass were prospectively randomized to cardiopulmonary bypass with or without retrograde autologous priming. Retrograde autologous priming was performed at the start of bypass by draining crystalloid prime from the arterial and venous lines into a recirculation bag (mean volume withdrawal: 880 +/- 150 ml). Perfusion and anesthetic techniques were otherwise identical for the two groups. The hematocrit value was maintained at a minimum of 16% and 23% during and after cardiopulmonary bypass, respectively, in all patients. Patients were well matched for all preoperative variables, including established transfusion risk factors. Subsequent hemodynamic parameters, pressor requirements, and fluid requirements were equivalent in the two groups.
  
  
  RESULTS
  The lowest hematocrit value during cardiopulmonary bypass was 22% +/- 3% versus 20% +/- 3% in patients subjected to retrograde autologous priming and in control patients, respectively (p = 0.002). One (3%) of 30 patients subjected to retrograde autologous priming had intraoperative transfusion, and seven (23%) of 30 control patients required transfusion during the operation (p = 0.03). The number of patients receiving any homologous red cell transfusions in the two groups during the entire hospitalization was eight of 30 (27%; retrograde autologous priming) versus 16 of 30 (53%; control) (p = 0.03).
  
  
  CONCLUSIONS
  These data suggest that retrograde autologous priming is a safe and effective means of significantly decreasing hemodilution and the number of patients requiring red cell transfusion during cardiac operations.
authors.affiliation: The New York Hospital-Cornell Medical Center, Department of Cardiothoracic Surgery, NY 10021, USA.
authors.forename: T K
authors.initials: TK
authors.lastname: Rosengart
authors.forename: W
authors.initials: W
authors.lastname: DeBois
authors.forename: M
authors.initials: M
authors.lastname: O'Hara
authors.forename: R
authors.initials: R
authors.lastname: Helm
authors.forename: M
authors.initials: M
authors.lastname: Gomez
authors.forename: S J
authors.initials: SJ
authors.lastname: Lang
authors.forename: N
authors.initials: N
authors.lastname: Altorki
authors.forename: W
authors.initials: W
authors.lastname: Ko
authors.forename: G S
authors.initials: GS
authors.lastname: Hartman
authors.forename: O W
authors.initials: OW
authors.lastname: Isom
authors.forename: K H
authors.initials: KH
authors.lastname: Krieger
mesh_terms: D000368:Aged; D016913:Blood Component Transfusion; D001804:Blood Transfusion, Autologous / Q000295:instrumentation / Q000379:methods; D002315:Cardiopulmonary Bypass / Q000295:instrumentation* / Q000379:methods*; D016022:Case-Control Studies; D005260:Female; D006400:Hematocrit; D006438:Hemodilution; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome